/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package com.googlecode.bluetools.dom4j.io;

import java.util.ArrayList;
import java.util.List;

import com.googlecode.bluetools.dom4j.Branch;
import com.googlecode.bluetools.dom4j.Document;
import com.googlecode.bluetools.dom4j.DocumentFactory;
import com.googlecode.bluetools.dom4j.Element;
import com.googlecode.bluetools.dom4j.Namespace;
import com.googlecode.bluetools.dom4j.QName;
import com.googlecode.bluetools.dom4j.tree.NamespaceStack;

/**
 * <p>
 * <code>DOMReader</code> navigates a W3C DOM tree and creates a DOM4J tree from it.
 * </p>
 * 
 * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
 * @version $Revision: 1.1 $
 */
public class DOMReader {
	/** <code>DocumentFactory</code> used to create new document objects */
	private DocumentFactory factory;

	/** stack of <code>Namespace</code> and <code>QName</code> objects */
	private NamespaceStack namespaceStack;

	public DOMReader() {
		this.factory = DocumentFactory.getInstance();
		this.namespaceStack = new NamespaceStack(factory);
	}

	public DOMReader(DocumentFactory factory) {
		this.factory = factory;
		this.namespaceStack = new NamespaceStack(factory);
	}

	/**
	 * DOCUMENT ME!
	 * 
	 * @return the <code>DocumentFactory</code> used to create document objects
	 */
	public DocumentFactory getDocumentFactory() {
		return factory;
	}

	/**
	 * <p>
	 * This sets the <code>DocumentFactory</code> used to create new documents. This method allows the building of
	 * custom DOM4J tree objects to be implemented easily using a custom derivation of {@link DocumentFactory}
	 * </p>
	 * 
	 * @param docFactory <code>DocumentFactory</code> used to create DOM4J objects
	 */
	public void setDocumentFactory(DocumentFactory docFactory) {
		this.factory = docFactory;
		this.namespaceStack.setDocumentFactory(factory);
	}

	public Document read(org.w3c.dom.Document domDocument) {
		if (domDocument instanceof Document) {
			return (Document) domDocument;
		}

		Document document = createDocument();

		clearNamespaceStack();

		org.w3c.dom.NodeList nodeList = domDocument.getChildNodes();

		for (int i = 0, size = nodeList.getLength(); i < size; i++) {
			readTree(nodeList.item(i), document);
		}

		return document;
	}

	// Implementation methods
	protected void readTree(org.w3c.dom.Node node, Branch current) {
		Element element = null;
		Document document = null;

		if (current instanceof Element) {
			element = (Element) current;
		}
		else {
			document = (Document) current;
		}

		switch (node.getNodeType()) {
		case org.w3c.dom.Node.ELEMENT_NODE:
			readElement(node, current);

			break;

		case org.w3c.dom.Node.PROCESSING_INSTRUCTION_NODE:

			if (current instanceof Element) {
				Element currentEl = (Element) current;
				currentEl.addProcessingInstruction(node.getNodeName(), node.getNodeValue());
			}
			else {
				Document currentDoc = (Document) current;
				currentDoc.addProcessingInstruction(node.getNodeName(), node.getNodeValue());
			}

			break;

		case org.w3c.dom.Node.COMMENT_NODE:

			if (current instanceof Element) {
				((Element) current).addComment(node.getNodeValue());
			}
			else {
				((Document) current).addComment(node.getNodeValue());
			}

			break;

		case org.w3c.dom.Node.DOCUMENT_TYPE_NODE:

			org.w3c.dom.DocumentType domDocType = (org.w3c.dom.DocumentType) node;
			document.addDocType(domDocType.getName(), domDocType.getPublicId(), domDocType.getSystemId());

			break;

		case org.w3c.dom.Node.TEXT_NODE:
			element.addText(node.getNodeValue());

			break;

		case org.w3c.dom.Node.CDATA_SECTION_NODE:
			element.addCDATA(node.getNodeValue());

			break;

		case org.w3c.dom.Node.ENTITY_REFERENCE_NODE:

			// is there a better way to get the value of an entity?
			org.w3c.dom.Node firstChild = node.getFirstChild();

			if (firstChild != null) {
				element.addEntity(node.getNodeName(), firstChild.getNodeValue());
			}
			else {
				element.addEntity(node.getNodeName(), "");
			}

			break;

		case org.w3c.dom.Node.ENTITY_NODE:
			element.addEntity(node.getNodeName(), node.getNodeValue());

			break;

		default:
			System.out.println("WARNING: Unknown DOM node type: " + node.getNodeType());
		}
	}

	protected void readElement(org.w3c.dom.Node node, Branch current) {
		int previouslyDeclaredNamespaces = namespaceStack.size();

		String namespaceUri = node.getNamespaceURI();
		String elementPrefix = node.getPrefix();

		if (elementPrefix == null) {
			elementPrefix = "";
		}

		org.w3c.dom.NamedNodeMap attributeList = node.getAttributes();

		if ((attributeList != null) && (namespaceUri == null)) {
			// test if we have an "xmlns" attribute
			org.w3c.dom.Node attribute = attributeList.getNamedItem("xmlns");

			if (attribute != null) {
				namespaceUri = attribute.getNodeValue();
				elementPrefix = "";
			}
		}

		QName qName = namespaceStack.getQName(namespaceUri, node.getLocalName(), node.getNodeName());
		Element element = current.addElement(qName);

		if (attributeList != null) {
			int size = attributeList.getLength();
			List attributes = new ArrayList(size);

			for (int i = 0; i < size; i++) {
				org.w3c.dom.Node attribute = attributeList.item(i);

				// Define all namespaces first then process attributes later
				String name = attribute.getNodeName();

				if (name.startsWith("xmlns")) {
					String prefix = getPrefix(name);
					String uri = attribute.getNodeValue();

					Namespace namespace = namespaceStack.addNamespace(prefix, uri);
					element.add(namespace);
				}
				else {
					attributes.add(attribute);
				}
			}

			// now add the attributes, the namespaces should be available
			size = attributes.size();

			for (int i = 0; i < size; i++) {
				org.w3c.dom.Node attribute = (org.w3c.dom.Node) attributes.get(i);
				QName attributeQName = namespaceStack.getQName(attribute.getNamespaceURI(), attribute.getLocalName(),
						attribute.getNodeName());
				element.addAttribute(attributeQName, attribute.getNodeValue());
			}
		}

		// Recurse on child nodes
		org.w3c.dom.NodeList children = node.getChildNodes();

		for (int i = 0, size = children.getLength(); i < size; i++) {
			org.w3c.dom.Node child = children.item(i);
			readTree(child, element);
		}

		// pop namespaces from the stack
		while (namespaceStack.size() > previouslyDeclaredNamespaces) {
			namespaceStack.pop();
		}
	}

	protected Namespace getNamespace(String prefix, String uri) {
		return getDocumentFactory().createNamespace(prefix, uri);
	}

	protected Document createDocument() {
		return getDocumentFactory().createDocument();
	}

	protected void clearNamespaceStack() {
		namespaceStack.clear();

		if (!namespaceStack.contains(Namespace.XML_NAMESPACE)) {
			namespaceStack.push(Namespace.XML_NAMESPACE);
		}
	}

	private String getPrefix(String xmlnsDecl) {
		int index = xmlnsDecl.indexOf(':', 5);

		if (index != -1) {
			return xmlnsDecl.substring(index + 1);
		}
		else {
			return "";
		}
	}
}

/*
 * Redistribution and use of this software and associated documentation ("Software"), with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions must also contain a
 * copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived from this Software without prior written
 * permission of MetaStuff, Ltd. For written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may "DOM4J" appear in their names without prior
 * written permission of MetaStuff, Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
